The invention relates to a furnace charge preheater in the form of a bucket for receiving the charge material to be heated by means of a heating gas, especially one to be used for scrap metal, having a bottom containing at least two half-shells which can be swung apart, within which bottom an annular gap is provided for the passage of hot gases.
A furnace charge preheater of this kind has been disclosed, for example, in DE-A1-No. 30 38 515. It can be used to preheat furnace charge materials such as scrap, ore, sponge iron, alloys, slag making material, etc., before they are charged into a melting furnace or converter, or into a roasting furnace. For the preheating of the charge material, hot exhaust gases from the melting furnace, for example, are passed through the charge preheater.
The charge preheater is constructed preferably as a scrap bucket having a bottom consisting of at least two hinged parts which can separate to drop its load, and in the bottom part of the bucket openings must be provided for the passage of the hot gases. In the known furnace charge preheater, when the bottom is in the closed state, an annular gap is provided between the outside of the bucket and the hinged bottom. After it is filled with the cold charge material, the bucket is placed with its bottom part in a chamber, and the chamber is sealed off above the annular gap between the wall and bottom of the bucket by means of two half-lids having semicircular cutouts. The top opening of the bucket is closed off by means of a hood. The hood is connected to the exhaust of a source of hot gas, and the chamber is connected to a filter house or exhaust stack with the interposition of a blower if desired. The hot exhaust gas is thus fed downwardly through the charge preheater, and it heats the charge and exits through the tightly closed chamber. It would also be possible to feed the hot gases through the chamber and exhaust the cooled gases from the hood placed on the preheater.
After the charge has been heated, the hood is swung aside, and the preheater can then be removed from the chamber and dumped into the melting furnace by swinging the bottom half-shells apart.
To achieve uniform heating of the charge in the known furnace charge preheater, vertical passages with downwardly directed gas outlets are distributed circumferentially about the inside wall of the bucket, and the bucket is filled with the use of an armature by which a passage is formed in the central part of the charge.
In a furnace charge preheater of the kind described above, it is the object of the invention to achieve a uniform flow of the hot gas through the charge materials without the need for additional procedures in loading the bucket.